Tools and methods for removing anchors from medical leads

ABSTRACT

Tools and methods for removing anchors from medical leads involve a guide portion and a blade. The lead is inserted within a lead passageway of the guide portion of the tool and the tool is moved along so that the blade contacts the anchor and cuts a slit in the anchor as the tool. Once the blade has cut the slit through the entire anchor, the anchor comes free of the lead and the tool can be removed. The tool may include a manner of opening and closing the guide portion so as to provide access to the lead when open and to contain the lead when closed. Opening the guide portion allows the lead to be inserted or removed by laterally moving the lead into or out of the lead passageway such that the tool may be installed or removed at any available point along the lead.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/436,986, filed Jan. 27, 2011, which application isincorporated herein in its entirety.

TECHNICAL FIELD

Embodiments are related to the removal of anchors from medical leads.More particularly, embodiments are related to tools and methods forremoval of the anchors.

BACKGROUND

Implantable medical devices that produce stimulation signals and/or thatsense physiological signals utilize implantable medical leads to carryelectrical signals. The implantable medical leads include electrodes ona distal end that interface with the bodily tissue. Electricalconductors within the medical lead electrically connect the electrodeson the distal end with electrical contacts on the proximal end thatengage electrical connectors of the medical device.

The medical lead is implanted within the body with the distal end beingrouted to the appropriate site to stimulate and/or sense. The proximalend of the lead remains nearby the incision site where the medicaldevice is also implanted and sutured to tissue. To ensure that the leadis also held in place, an anchor is installed on the lead, and theanchor is then sutured to tissue.

Conventionally, anchors were designed to slide over the lead body andthen be held tightly to the lead body by the suture. In such a case, theanchor could be removed by cutting the suture and then sliding theanchor off of a free end of the lead, typically the proximal end of thelead that is disconnected from the medical device. However, there may beother anchor designs that use elasticity to grip onto the lead body anddo not freely slide along the lead body. In that case, cutting thesutures that tie the anchor to the tissue does not result in the anchorbeing able to slide off of a free end of the lead such that the anchorremains affixed to the lead body.

SUMMARY

Embodiments address issues such as these and others by providing anchorremoval tools and methods for removing anchors from a lead body. Theembodiments provide for attaching a tool to the lead body by placing thelead within a lead passageway within a guide portion of the anchor tool.The embodiments further provide for sliding the tool along the lead bodyto engage a blade of the tool against the anchor and to cut through theanchor thereby releasing the anchor from the lead body.

Embodiments provide an implantable medical lead anchor removal tool thatincludes a first body including a guide portion having an inner leadpassageway having a longitudinal dimension. A second body is movablycoupled to the first body, the inner lead passageway being opened alongthe longitudinal dimension when the second body is moved relative to thefirst body. A blade is present within the first body, and the blade hasa cutting edge that is at least partially exposed from the first bodyand that is aligned so that a plane defined by the blade intersects withthe guide portion in the first body.

Embodiments provide a method of removing an anchor from an implantablemedical lead that involves opening a lead passageway within a guideportion of an anchor removal tool along a longitudinal dimension of thelead passageway. The method may involve introducing the lead into theopening of the lead passageway along the longitudinal dimension. Themethod may involve closing the lead passageway within the guide portionof the anchor removal tool once the lead has been introduced into thelead passageway. Additionally, the method may involve sliding the anchorremoval tool along the lead with the lead passing through the guideportion such that a blade of the anchor removal tool cuts through theanchor.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side view of an example of an anchor removal toolaccording when in a closed position.

FIG. 2 shows a side view of the example in an open position.

FIG. 3 shows an opposite side view of the example in the open position.

FIG. 4 shows a front view of the example in the open position.

FIG. 5 shows a front view of the example in the closed position.

FIG. 6 shows a top view of the example in the closed position.

FIG. 7 shows a side view of a second example with a clip in a closedposition.

FIG. 8 shows an opposite side view of the second example with the clipin an open position.

FIG. 9 shows a front view of the second example with the clip in theclosed position.

FIG. 10 shows a top view of the second example with the clip in theclosed position.

FIG. 11 shows a side view of the second example with the clip omitted.

FIG. 12 shows a front view of the clip.

FIG. 13 shows a side view of the first example being used to remove ananchor from a lead.

FIG. 14 shows a side view of the second example being used to remove theanchor from the lead.

DETAILED DESCRIPTION

Embodiments provide anchor removal tools and methods of removing anchorsfrom implantable medical leads. The anchor removal tools include a bladethat is used to cut through the anchor while also including a leadpassageway that the lead passes through as the tool is removing theanchor from the lead. The anchor removal tools may provide structuresfor opening and closing access to the lead passageway such that the leadcan be inserted into the lead passageway when open and may then becaptured within the lead passageway when closed where the anchor toolmay then move along the lead without the lead coming free from the leadpassageway.

FIG. 1 shows one example of an anchor removal tool 100 in a closedposition. The anchor removal tool 100 includes a first body 102 and asecond body 104 that are coupled together by a hinged coupling 106. Inthis particular example, the first body 102, second body 104, and thehinged coupling 106 are integral to one piece of material of the tool100, but it will be appreciated that one or more of these could be aseparate piece that is attached to an adjacent piece. In this example,the one piece of material is formed such that the hinged coupling 106has a relatively thin construction so as to sharply bend to provide thehinge function. The hinged coupling 106 may have a normal state that thehinged coupling 106 is biased toward, such as the open position so thatwhen released from the closed position by the user the tool 100 beginsto open about the hinged coupling 106. The first and second bodies 102,104 and the hinged coupling 106 may be made of various rigid materialssuch as various types of a polymer like polypropylene.

The first body 102 houses a blade 108 that is at least partially exposedsuch that a cutting edge of the blade 108 is also exposed. The cuttingedge of the blade 108 ultimately contacts the anchor to slice throughthe anchor and ultimately release the anchor from the lead body. Theblade 108 may be made of a rigid material capable of having a cuttingedge suitable for cutting through an anchor material like siliconerubber. For instance, the blade 108 may be various types of metal likestainless steel. The first body 102 may be molded about the blade 108 orthe blade 108 may be otherwise installed within a compartment within thefirst body 102.

The first body 102 of this example also includes a guide portion 110which serves to guide the tool 100 along the lead body. The guideportion 110 defines the lead passageway 112 where the lead is placed.The lead slides through the lead passageway 112 as the tool 100 movesalong the lead to approach and cut through the anchor.

The second body 104 closes the lead passageway 112 so that the leadcannot move laterally out of the lead passageway 112 but can only slidein the longitudinal dimension of the lead passageway 112. Thus, thepresence of the second body 104 ensures that the lead remains within thelead passageway 112 as the tool 100 slides along the lead to approachand cut through the anchor.

To assist the user in sliding the tool 100 along the lead and throughthe anchor, the first and second bodies 102, 104 include protrusions 116that allow the user to obtain a better grip on the tool 100. Theprotrusions 116 are oriented at an angle relative to the longitudinaldimension of the lead passageway 112 such that when force is applied bythe user in the longitudinal dimension of the guide portion 110 in orderto move the tool 100 and cut the anchor, the protrusions 116 provide asurface that opposes slippage of the grip by the user.

To further assist the user in sliding the tool 100, the first and secondbodies 102, 104 include side indentations 118, 119, as shown in FIG. 2,that are shaped to receive the pinch of a finger and thumb. The firstand second bodies 102, 104 may include edge indentations 115, 117 alonga top edge which form a common indentation 114 when the second body 104is closed relative to the first body 102 as in FIG. 1. The alignment ofthe indentations 115 and 117 to form the common indentation 114 can beseen in the top view of FIG. 6. The edge indentation 114 may also beshaped to receive a finger such as where the user prefers to press onthe top edge with a thumb or pointer finger when sliding the tool 100.

FIG. 2 shows an open tool 100′ from one side while FIG. 3 shows the opentool 100′ from the opposite side. This example includes arcuate shapesfor the first and second bodies 102, 104 which form an arcuate handle inthe closed position as shown in FIG. 1. Here the second body 104 hasbeen opened from the first body 102 by rotation of the second body 104relative to the first body 102 at the hinged coupling 106. The result ofopening the second body 104 relative to the first body 102 is that thelead passageway 112 within the guide portion 110 is open along thelongitudinal dimension of the lead passageway 112 as seen most clearlyin FIG. 3. This opening of the lead passageway 112 allows the lead to beinserted by lateral movement of the lead and thus at any available pointalong the lead rather than requiring the proximal or distal end of thelead to be inserted axially into the lead passageway 112. In thisparticular example, the second body 104 includes a guide portion 120that cooperates with the guide portion 110 to further close the leadpassageway 112 when the second body 104 is closed relative to the firstbody 102.

FIG. 3 also shows that the guide portion 110 and lead passageway 112 ofthis example have a taper. The small diameter end of the taper is at thefront of the tool 100 that approaches the anchor. Thus, the smalldiameter end of the taper of the guide portion 110 allows the guideportion 110 to begin to slide between the lead body and the anchor asthe tool 100 is pressed forward into the anchor. As the anchor slides upthe tapered end of the guide portion 110, the anchor encounters theblade 108 which begins to cut through the anchor. As the lead passageway112 tapers to a larger diameter, there is less drag created due to lessimpactful contact with the length of the lead body within the leadpassageway 112.

FIG. 4 shows a front view of the opened tool 100′ where the relationshipof the blade 108 to the guide portion 110 and lead passageway 112 isfurther depicted. Here it can be seen that a plane created by the blade108 intersects with the guide portion 110 so as to completely cutthrough the anchor that is encountering the guide portion 110. In thisparticular example, the plane of the blade 108 also intersects with thelead passageway 112 to create a more radial cut through the anchor. Theopen side of the lead passageway 112 which allows the lead to beinserted by moving the lead in a lateral direction, and thus at anyavailable point along the lead, can also be seen in FIG. 4.

FIG. 5 shows a front view of the closed tool 100. Here the relationshipof the blade 108, the guide portion 110 of the first body 102 and theguide portion 120 of the second body 104 can be seen. The guide portion120 closes the longitudinal opening to the lead passageway 112 withinthe guide portion 110 so as to create an enclosed path for the leadwhich also isolates the lead from the blade 108.

FIG. 7 shows another example of an anchor tool 200 in a closed position.This example includes a first body 202 and a second body 204 that isslidably coupled to the first body 202. The first body 202, second body204, as well as a blade 208 of the tool 200 may be constructed of thesame materials discussed above for the anchor tool 100. The first body202 defines a handle that the user may grasp, in this case with anarcuate shape but other shapes are also possible. In this example, thefirst body 202 includes protrusions 216 as well an edge indentation 214and side indentations 215, 217 to allow the user to have an adequategrip while sliding the tool 200 along the lead. FIG. 10 is a top viewthat further illustrates the edge indentation 214 and the aligned sideindentations 215 and 217 that are present within the first body 204 ofthis example.

The first body 202 includes a guide portion 210 that defines a leadpassageway 212 that the lead may pass through. A blade 208 is exposedfrom the first body 202 and forms a plane that intersects with the guideportion 210 so as to cut through the anchor. The guide portion 210 canbe opened to reveal the lead passageway 212 by movement of the secondbody 204 relative to the first body 202.

The second body 204 is attached to the first body 202 such that when thesecond body 204 is in a closed position as shown in FIG. 7, the secondbody 204 closes the opening in the guide portion 210 to the leadpassageway 212. The user can slide the second body 204 upward in thisexample to expose the opening in the guide portion 210 as shown in FIG.8 which allows the lead to be inserted along the longitudinal opening.For instance, the lead may be moved laterally, and hence at anyavailable location along the lead body, into the lead passageway 212through the longitudinal opening in the guide portion 210. The user canthen slide the second body 204 downward in this example to the closedposition shown in FIG. 7 to contain the lead within the lead passagewaywhile allowing the tool 200 to slide along the lead.

The relationship of the second body 204 to the guide portion 210 and thelead passageway 212 can be further seen in the front view of FIG. 9.Here the second body 204 is in the closed position to enclose the leadpassageway 212. In this example, the second body 204 includesprotrusions 222 which provide additional grip for the user when graspingthe second body 204 in order to raise or lower the second body 204relative to the first body 202. The protrusions 222 may be present onboth sides of the second body 204 as shown in FIG. 9 so that there isadditional grip for both fingers pinching the second body 204 to raiseor lower to the second body 204.

FIG. 11 shows the first body 202 with the second body 204 removed forpurposes of illustration. The first body 202 includes a recess 224 inthe area where the second body 204 is normally present. The recess 224,which may be present in the same area on both sides of the first body202, provides a structure for attachment of the second body 204.Additionally, the recess 224 may constrain the sliding movement of thesecond body 204 relative to the first body 202. The recess 224 may alsoinclude features, such as horizontal grooves at stop positions to holdthe second body 204 at a fixed position, such as open or closed, untilforced to the opposite position by the user. Other structures may alsobe used for attachment of the second body 204. For instance, the secondbody 204 could be attached to the first body 202 by a hinge such thatthe second body 204 pivots forward to open the lead passageway 212.

FIG. 12 shows a front view of the second body 204. This front viewreveals inner protrusions 226 that are present on the inner walls of thesecond body 204. These inner protrusions 226 engage the recess 224 ofthe first body 202 as shown in FIG. 11 in order to retain the secondbody 204 on the first body 202 and to define the path of movement of thesecond body 204 relative to the first body 202. To the extent the recess224 may have features to provide stop positions to hold the second body204 in place, the protrusions 226 may engage those features to hold thesecond body 204 in place until forced to the opposite position by theuser.

FIG. 13 shows the operation of the anchor tool 100. At this point, thelead 300 has been inserted into the lead passageway 112 of the anchortool 100 which is now closed. The lead 300 may have been inserted byfeeding a free end of the lead 300 into the end of the lead passageway112 if a free end is available. Alternatively, the lead 300 may beintroduced at any available location along the lead by insertion alongthe longitudinal opening of the guide portion 110 while the anchor tool100 is hinged open. For instance the lead 300 may be moved laterallythrough the longitudinal opening of the guide portion 110. The anchortool 100 is then closed to contain the lead 300 within the leadpassageway 112.

The anchor tool 100 is then slid along the lead until encountering theanchor 302. Upon encountering the anchor 302, the anchor 302 begins toslide onto the leading edge of the guide portion 110 and encounters theblade 108 which slices through the anchor 302. If the anchor is stillsutured in place, the sutures may also be cut by the blade 108. Thesliced open portion 304 of the anchor 302 then peels away from the lead300 as the anchor tool 100 continues to slide along the lead 300 untilcutting through the entire length of the anchor 302. At that point theanchor 302 is no longer present on the lead and the anchor tool 100 canbe removed by the tool 100 being hinged open and pulling the lead 300out through the longitudinal opening, such as by laterally moving thelead 300 with the tool 100 at any point along the lead 300.Alternatively, the anchor tool 100 can be slid along the lead 300 ineither direction and off of a free end if one is available.

FIG. 14 shows the operation of the anchor tool 200. At this point, thelead 300 has been inserted into the lead passageway 212 of the anchortool 200 which is now closed. The lead 300 may have been inserted byfeeding a free end of the lead 300 into the end of the lead passageway212 if a free end is available. Alternatively, the lead 300 may beintroduced at any available location along the lead by insertion alongthe longitudinal opening of the guide portion 210 while the anchor tool200 is open by sliding the second body 204. For instance the lead 300may be moved laterally through the longitudinal opening of the guideportion 210. The anchor tool 200 is then closed by sliding down thesecond body 204 to contain the lead 300 within the lead passageway 212.

The anchor tool 200 is then slid along the lead until encountering theanchor 302. Upon encountering the anchor 302, the anchor 302 begins toslide onto the leading edge of the guide portion 210 and encounters theblade 208 which slices through the anchor 302. If the anchor is stillsutured in place, the sutures may also be cut by the blade 208. Thesliced open portion 304 of the anchor 302 then peels away from the lead300 as the anchor tool 200 continues to slide along the lead 300 untilcutting through the entire length of the anchor 302. At that point theanchor 302 is no longer present on the lead 300 and the anchor tool 200can be removed by the second body 204 being moved upward relative to thefirst body 202 and pulling the lead 300 out through the longitudinalopening, such as by laterally moving the lead 300 with the tool 200 atany point along the lead 300. Alternatively, the anchor tool 200 can beslid along the lead 300 in either direction and off of a free end if oneis available.

While embodiments have been particularly shown and described, it will beunderstood by those skilled in the art that various other changes in theform and details may be made therein without departing from the spiritand scope of the invention.

What is claimed is:
 1. An implantable medical lead anchor removal tool,comprising: a first body including a guide portion having an inner leadpassageway having a longitudinal dimension defined along the length ofthe guide portion; a second body movably coupled to the first body by acoupling providing an axis of rotation of the second body relative tothe first body where the axis of rotation is parallel to thelongitudinal dimension from at least one perspective perpendicular tothe longitudinal dimension, the second body having a protrusion that ispresent within the inner lead passageway, the inner lead passagewaybeing opened along the longitudinal dimension when the second body ismoved relative to the first body about the axis of rotation of thecoupling to thereby remove the protrusion of the second body from theinner lead passageway, wherein at least one of the first body and thesecond body provides an elongated portion including an arcuate top edgeand an arcuate bottom edge where a radius of curvature of both thearcuate top edge and the arcuate bottom edge has a center point spacedfrom the bottom edge in a direction away from the top edge and whereinthe arcuate top edge and the arcuate bottom edge span more than half ofa length of the elongated portion; and a blade present within the firstbody, the blade having a cutting edge that is at least partially exposedfrom the first body and that is aligned so that a plane defined by theblade intersects with the guide portion in the first body such that theblade contacts the guide portion where the guide portion forms the innerlead passageway and with the entire blade being outside of the innerlead passageway.
 2. The implantable medical lead anchor of claim 1,wherein the coupling comprises a hinged coupling and wherein the firstbody and the second body are hingedly coupled such that the second bodyrotates at the hinged coupling to move relative to the first body. 3.The implantable medical lead anchor of claim 2, wherein the first body,the second body, and the hinged coupling are integral to a tool body. 4.The implantable medical lead anchor removal tool of claim 2, furthercomprising an edge indentation in a first edge of the first body and anedge indentation in a first edge of the second body, wherein the edgeindentation in the first body and the edge indentation in the secondbody become aligned and form a common edge indentation when the firstbody and the second body are brought together by rotation at the hingedcoupling.
 5. The implantable medical lead anchor removal tool of claim2, further comprising a side indentation in a first side of the firstbody and a side indentation in a first side of the second body, whereinthe side indentation of the first body and the side indentation of thesecond body become aligned when the first body and the second body arebrought together by rotation about the hinged coupling.
 6. Theimplantable medical lead anchor removal tool of claim 1, furthercomprising: a plurality of protrusions present on an outer surface ofthe first body and the second body, the protrusions being oriented at anangle relative to the longitudinal dimension of the guide portion. 7.The implantable medical lead anchor removal tool of claim 1, whereinboth the first body and the second body have top and bottom edges thatare arcuately shaped.
 8. The implantable medical lead anchor removaltool of claim 1, further comprising: a plurality of protrusions presenton opposing outer surfaces of the first body, the protrusions beingoriented at an angle relative to the longitudinal dimension of the guideportion.
 9. The implantable medical lead anchor removal tool of claim 1,further comprising an edge indentation in a first edge of the firstbody.
 10. The implantable medical lead anchor removal tool of claim 1,further comprising a side indentation in opposing sides of the firstbody.
 11. The implantable medical lead anchor removal tool of claim 1,wherein the first body has the top edge and the bottom edge that arearcuately shaped.
 12. The implantable medical lead anchor removal toolof claim 1, further comprising a plurality of protrusions present onopposing outer surfaces of the second body.
 13. The implantable medicallead anchor removal tool of claim 1, wherein the inner lead passagewayhas an opening at both ends with each opening being present when thesecond body moves relative to the first body.